This program's primary purpose is to train physicians for careers in biomedical research. In the past we focused on training physicians to do laboratory research, but recently we have begun to train physicians to do either laboratory or patient-oriented research (with an emphasis on translational clinical research). We accept 1-2 physicians/year and they will train for three years (a total of 6 positions). Physicians will enter this training program after they have completed residency training in either Internal Medicine or Pediatrics. The program will also train a small number of Ph.D. postdoctoral fellows to do research on infectious diseases, with an emphasis on microbial pathogenesis. By mixing M.D. and Ph.D. postdoctoral fellows in the same program, we enhance the educational experience of both groups. Ph.D. scientists will generally enter our program immediately after they earn their degrees, but some may have had one or more years of postdoctoral training. All physicians who train to do laboratory research will be encouraged to continue their training for another 2-3 years beyond the period supported by the training grant. We use University Hospital, the VA Medical Center, and the Antiviral Research Center (AVRC) for clinical research training, and the research laboratories of the faculty members listed below for the laboratory research training. Laboratory research fellows will enroll in appropriate courses taught by the Biology Department at UC San Diego. We will allow fellows to train in laboratories of other UCSD faculty if appropriate. Fellows entering the clinical research track also will have the opportunity to work in appropriate research laboratories to learn specific techniques. All fellows doing patient-oriented research will enroll in the NIH-supported Clinical Research Enhancement through Supplemental Training (CREST) course. They will also be able to enroll in courses at the School of Public Health at San Diego State University and have the opportunity to obtain an MPH degree. Dr. Joshua Fierer will be responsible for the overall direction of training, and Dr. Allen McCutchan will be responsible for the patient-oriented research component. Dr. Stephen Spector will supervise the Pediatric research physicians. [unreadable] [unreadable]